Sensitivity Analysis for Polymer Injection to Improve Heavy Oil Recovery – Small-Scale Simulation Study

Abstract

Polymer flooding has been widely used for enhancing oil recovery, due to the growing number of successful applications around the world. The process aims to increase water viscosity and, thus, decrease the water/oil mobility ratio, thereby improving sweep efficiency. The understanding of the physical mechanisms involved in this enhanced oil recovery process allows us to forecast the application potential of polymer flooding. This work aims to assess physical phenomena associated with heavy oil recovery through polymer flooding using 1D small-scale simulation models. We evaluate the influence of different levels of adsorption, accessible pore volume, residual resistance factor, and polymer concentration on the results and compare their magnitude effect on the results. The models used in this study were built using data from previous lab work and literature. For each one of the mentioned parameters, this work compares the histories of water cut, cumulative water-oil ratio, average pressure, and oil recovery factor. Additionally, water saturation, water viscosity, and water mobility profile were determined for specific periods of the flooding process. The sensitivity analyses showed that high levels of adsorption influence the polymer loss of the advance front, delaying oil recovery. Low values of accessible pore volume lead to a slightly faster polymer breakthrough and oil recovery anticipation. A high residual resistance factor increases the average pressure and improves oil recovery. Higher polymer concentration enhances the displacement efficiency and enhances the recovery factor.